Phenolic compounds and antioxidant capacities of 10 common edible flowers from China.

The free and bound phenolic compounds in 10 common Chinese edible flowers were investigated using reversed phase high-performance liquid chromatography. Their antioxidant capacities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging activity, oxygen radical absorption capacity (ORAC), ferric reducing antioxidant power (FRAP), and cellular antioxidant activity (CAA). Free factions were more prominent in phenolic content and antioxidant capacity than bound fractions. Paeonia suffruticosa and Flos lonicerae showed the highest total phenolic content (TPC) 235.5 mg chlorogenic acid equivalents/g of dry weight and total flavonoid content 89.38 mg rutin equivalents/g of dry weight. The major phenolic compounds identified were gallic acid, chlorogenic acid, and rutin. P. suffruticosa had the highest antioxidant capacity in the DPPH, ABTS, and ORAC assays, which were 1028, 2065, 990 μmol Trolox equivalents/g of dry weight, respectively, whereas Rosa chinensis had the highest FRAP value (2645 μmol Fe(2+) equivalents /g of dry weight). The P. suffruticosa soluble phenolics had the highest CAA, with the median effective dose (EC50 ) 26.7 and 153 μmol quercetin equivalents/100 g of dry weight in the phosphate buffered saline (PBS) and no PBS wash protocol, respectively. TPC was strongly correlated with antioxidant capacity (R = 0.8443 to 0.9978, P < 0.01), which indicated that phenolics were the major contributors to the antioxidant activity of the selected edible flowers.

Xiong L ，Yang J ，Jiang Y ，Lu B ，Hu Y ，Zhou F ，Mao S ，Shen C ... -  《-》

Phenolic Profiles, Antioxidant Activities, and Neuroprotective Properties of Mulberry (Morus atropurpurea Roxb.) Fruit Extracts from Different Ripening Stages.

The present work investigated the phenolic profiles (including nonanthocyanin and anthocyanin phenolics), antioxidant activities, and neuroprotective potential of mulberry fruit (MF) (Morus atropurpurea Roxb.) grown in China at different ripening stages. High-performance liquid chromatography-tandem mass spectrometry method (HPLC-MS/MS) was used to identify and quantify the phenolic compounds. The antioxidant capacity, total phenolic content (TPC), total flavonoid content (TFC), and total monomeric anthocyanin content (TAC) were determined using spectrophotometric methods. The neuroprotective effects of MFs at different ripening stages were investigated using Aβ25-35 -treated PC12 cells as the cellular model of Alzheimer's disease. Of the 19 phenolic compounds characterized from the MF extracts, the contents of rutin and anthocyanins increased and that of chlorogenic acid decreased significantly with maturity. At the fully ripened stage, MF extracts showed the highest amounts of TPC (11.23 mg gallic acid equivalents/g fresh weight), TFC (15.1 mg rutin equivalents/g fresh weight), and TAC (1177 mg cyanidin 3-O-glucoside equivalents/100 g fresh weight). Meanwhile, antioxidant activity of MF extracts at this stage was highest according to ABTS (an IC50 value of 4.11 μg/mL) and DPPH (an IC50 value of 10.08 μg/mL) assays. Cellular assays revealed increased cell viability in cells treated with the ripe MF extracts; compared with the control groups, the ripening fruits also increased the antioxidant enzyme levels in PC12 cells. Together, these results suggest that the antioxidant activities and neuroprotective properties of ripening MFs are related to the contents and types of phenolic compounds that are present in the fruits.

Yang J ，Liu X ，Zhang X ，Jin Q ，Li J ... -  《-》

Vitamin C equivalent antioxidant capacity (VCEAC) of phenolic phytochemicals.

Kim DO ，Lee KW ，Lee HJ ，Lee CY ... -  《JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY》

Investigation into the antioxidant activity and chemical composition of alcoholic extracts from defatted marigold (Tagetes erecta L.) residue.

The influence of various solvents on the yield of polyphenols from defatted marigold residue, the antioxidant activity of the extracts and the composition of antioxidant compounds in the extracts were investigated. The content of total phenolics and flavonoids in the extracts was significantly varied with different solvents (P<0.05) and the extract by ethyl alcohol (EtOH)/water (7:3, v/v) has the highest content of total phenolics and flavonoids, 62.33 mg gallic acid equivalents (GAE)/g and 97.00 mg rutin equivalent (RE)/g, respectively. The antioxidant activity of the extracts was evaluated by radical (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH)) scavenging and ferric reducing antioxidant power (FRAP) assays. The results of the correlation analysis showed that the antioxidant activity was well correlated with the content of total phenolics and flavonoids (R²>0.900). Antioxidant components in the extracts were identified by combined on-line HPLC-ABTS·+ post-column assay and HPLC-DAD-MS method. Gallic acid, gallicin, quercetagetin, 6-hydroxykaempferol-O-hexoside, patuletin-O-hexoside and quercetin were the dominant antioxidant compounds in the extracts, and quercetagetin was identified as the strongest antioxidant capacity.

Gong Y ，Liu X ，He WH ，Xu HG ，Yuan F ，Gao YX ... -  《-》

Phenolic Profiles and Contribution of Individual Compounds to Antioxidant Activity of Apple Powders.

Apples (Malus domestica L.) are the most common source of phenolic compounds in northern European diet. Besides pectins, dietary fibers, vitamins, and oligosaccharides they contain phenolic compounds of different classes. Apple powders are convenient functional forms retaining significant amounts of phenolic antioxidants. In this study reducing and radical scavenging profiles of freeze-dried powders of "Aldas,ˮ "Auksis,ˮ "Connel Red,ˮ "Ligol,ˮ "Lodel,ˮ and "Rajkaˮ were determined and phenolic constituents were identified using ultra high-performance liquid chromatography coupled to quadrupole and time-of-flight mass spectrometers. A negative ionization mode was applied and seventeen compounds: phenolic acids (coumaroylquinic, chlorogenic), flavonoids (quercetin derivatives), and procyanidin derivatives (B1, B2, and C1) were identified in all tested apple samples. Total values of Trolox equivalents varied from 7.72 ± 0.32 up to 20.02 ± 0.52 and from 11.10 ± 0.57 up to 21.42 ± 0.75 μmol/g of dry weight of apple powder in FRAP (ferric reducing antioxidant power) and ABTS (2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) postcolumn assays, respectively. The greatest Trolox equivalent values were determined for apples of "Aldasˮ cultivar. Chlorogenic acid and procyanidin C1 were the most significant contributors to total reducing and radical scavenging activity in all apple cultivars tested, therefore they could be considered as markers of antioxidant activity.

Raudone L ，Raudonis R ，Liaudanskas M ，Viskelis J ，Pukalskas A ，Janulis V ... -  《-》